Grinding-mill



3 Sheets-Sheet-3.

J. T. CASE. Grinding Mill.

No. 232,595. Patented Sept. 28, I880.

i UNiTED STATES PATENT OFFICE;

JOEL T. CASE, OF BRISTOL, CONNECTICUT.

GRINDING-MILL.

SPECIFICATION forming part of Letters Patent No. 232,595, dated September 28, 1880.

Application filed September 18, 1879.

To an whom it may concern:

Be it known that I, JOEL T. CASE, of Bristol, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Grinding-Mills, of which the following is a specification.

In the accompanying drawings, Figure 1 is a side elevation of a mill which embodies my invention. Fig. 2 is a vertical section of the same, taken on a plane running through the airfiues. Fig. 3 is a horizontal section of the same on line 00 w of Fig. 2. Fig. 4 is a plan view of the hopper. Fig. 5 is a plan view of the said mill with the hopper detached, and Fig. 6 is an under-side face view of the upper stone.

The complete device is supported by the flange a, which is designed to rest upon afloor or other suitable base or platform, as indicated by the line A, Fig. 1. This flange a, Fig. 1, is formed at the upper edge of the lower half of the case which contains the running stone, and

therefore in substantially the same plane as the upper face of the running stone. This construction makes the mill specially adapted for being supported by this flange when the latter rests upon a floor, in which-case the running stone'is in the same plane with the timbers which support the floor, and therefore in a position to receive the greatest amount of lateral support against vibration which any part of the building is capable of giving to it, and also to utilize said support in a very economical manner.

The caseB B is, for convenience, made in two halves. The upper stone, O, is incased in an iron frame and supported and adjusted within the upper half, B, of the case by means of adjusting-screws, in such manner as to leave an air-space between it and the top of the case, as shown in Fig. 2. The lower half, B, of the case has an annular groove in it, which receives the annular upper end of the pulley-frame D, the same being held in place and adjusted to any desired position relatively to each other by means of the set-screws 1), Figs. 1 and 3. In the lower end of this frame is the adjustable step c, for adjusting the shaft E. The under stone, F, is connected directly thereto and mounted in a suitable frame on the shaft E,

underneath which frame there is a fan, G, Figs. 2 and 3, which, being thus mounted,

, necessarily moves with the stone.

lower end of the shaft E, and within the frame D, there is a driving-pulley, H.

. The central opening in the bottom of the case is large enough to admit air to the fan G, as shown in Fig. 2.

Upon each side of the case there is an airflue, (1, leading from the chamber which incloses the fan to the air-space c, Fig. 2, above the upper stone, 0, which stone has four airpassages, f, Figs. 2 and 6, made vertically through it to conduct the air-blast to the faces of the stone, and from thence through the fur rows to the surrounding air-space in the case, and also, to some extent, upward through the hopper.

Upon the top of the case is a regulator, which Upon the consists of an annular ring, g, in a like groove,

and provided with openings which register with corresponding openings in the top of the case, as shown in Fig. 5. By turning the ring 9 so as to leave more or less of the openings in the case uncovered more or less air will escape thereat, and consequently the force of the blast through the stones will be correspondingly decreased; or if the regulator is entirely closed the whole force of the blast may be directed through the stones.

I am aware that an air-blast has been before employed in grinding-mills, and I hereby disclaim the same. In none of the prior mills was the fan inclosed in the same case with the stones, so far as I know, although one patent shows a fan inclosed in a separate case immediately above the case which iucloses the upper stone. In my case the frames which receive and hold the respective stones are fit ted to the interior of the case, so as to efiectually close the upper and lower ends thereof,

even when adjusted to different heights there- By this arrangement the air-space.

theair-space above both stones, the fresh air drawn in and forced through by the fan is carried to all sides of the stones, and by a very compact andinexpensive means. Instead of feeding the grain into the hopper Iin small quantities by means of shaking devices, I fill the hopper substantially full atone time and keep quite a quantity in it. A small opening, h, on one side of the shaftE leads to the stones, and so much of which opening as is not filled by the shaft is covered and regulated by the slide 70. The complete opening, including that occupied by the shaft, as well as that on one side of said shaft, is of an oblong form. A small projection, m, is formed on the side of the shaft E just above the opening h, so that said projection, together with the friction of the grain on the sides of the revolving shaft which extends upward through the bottom of the hopper, has the tendency to agitate the grain sufficiently to prevent it from clogging, and to always keep the opening free without any other device or devices whatsoever.

It should be noticed that the shaft which extends up into the hopperis the one to which the stones are hung, whereby all couplings are dispensed with and are useless. Furthermore, that the vertical adj ustmentof said shaft to regulate-the stones does notin any manner interfere with the feeding mechanism.

When this feed is used in connection with an air-blast which is forced through the eye of the stone under the hopper I place a drafttube with its open end extending down into the small part of the hopper to a point not far above the opening h, through which tube the hulls, dust, and lighter material will be forced upward and out by the air-blast, and thereby not only prevent the same from clogging the feed, but also clean the grain on its passage to the stones.

The step 0, and consequently the distance between the stones, is regulated by means of the lever K and adjusting-rod L, the latter of which extends upward through the platform A.

I am awarethat a prior patent shows a pulley-stand adapted to rest upon a floor, and

having an annular recess in its upper side, so that a case may rest therein, but without any means for preventing axial movement of one part upon the other, or to prevent the pulleystand from falling when the case is suspended or supported by any means other than said pulley-frame; also one showing projections on a shaft in a cylindrical hopper having a conical bottom and openings for discharging its contents radially instead of axially, both of which prior devices are hereby disclaimed. I claim as my inventionj 1. The case B B, having a chamber for inclosin g both stones, and underneath said chamber a chamber for inclosing the fan G, and above the upper stone an inclosing airspace connected with the fan-chamber by airpassages d extending along by the outside edges of the stones, and all inclosed by the case B B, substantially as described, and for the purpose specified.

2. The case B B, having an air-space above both stones and a fan-chamber below both stones, in combination with the frames which receive and hold the stones, said frames being fitted to the respective ends of said case, so as to effectually close said ends when adjusted to different heights, substantially as described, and for the purpose specified.

3. The case B B, having an annular airspace surrounding the stones and air-fines dd upon the outside of said annular air-space, both inclosed by one and the same case, substantially as described, and for the purpose specified.

at. The conical hopper I, having an oblong opening near the center and lower end thereof, in combination with the main shaft, which fills one end of said opening, and the slide 70 for closing the other end thereof, substantially as described, and for the purpose specified.

JOEL '1. CASE. Witnesses:

JAMES SHEPARD, JOHN EDWARDS. 

